BiM is a calculator alternative to the default OS X calculator and is built on the UNIX program "bc". BiM offers features such as a historical view of previous calculations, a library of math and conversion functions, and automatic variable assignment to calculations.
Boolean Calculator is a simple utility for technical informatics on university. You can enter a formular like "a and b and (not c)" and it shows you a table where you can see on which boolean combination of a, b and c the term is true.
Calindock brings a simple but attractive monthly or daily calendar to the Dock. Cycle through 1, 3, 6 or 12 months with the click of your mouse. Toggle between a monthly or daily calendar view. Start your week on Sunday or Monday as you prefer. Fully localized for English, Japanese, German and Spanish languages.
Calq is an easy to use, on demand calculator. The idea behind Calq is to have a calculator handy when you need it do some basic calculations quickly. It's there when you need it, and it's not in the way when you don't need it.
EdenMath is a scientific calculator which does standard arithmetic, probability, and trigonometric functions. This tool is primarily focused for users of Mac OS 10.1, but it is certainly useable with later Macintosh operating systems.
HeroCalc is powerful. Its superpowers include graphs, variable and function definitions, imaginary numbers, and more! - See more at: http://herocalc.com/#sthash.cKul1tUd.dpuf
HPConnect attempts to provide Mac users the same basic functionality that PC users get from HPConn4x. It uses a simple user interface.
LiveCalc is an interactive realtime text calculator. This tool calculates an expression, while you are typing it.
Longhand is a calculator built from the ground up to facilitate calculation.
LXVII (pronounced "67") is a new calculator program that is based on the Hewlett-Packard HP-67 programmable calculator. LXVII is a faithful simulation, but not exact emulator, of the HP-67. It has the same number memory registers and program steps as the original. The stack depth is the same (4 cells), the button and prefix key layout is also the same.
Magic Number Machine
Magic Number Machine is a free, full-featured, graphically laid out, high-precision, scientific calculator for Mac OS X 10.4 and greater. Full source-code is included with the distribution.
Mini Calculator allows you to perform powerful complex inline calculations in a small global floating window.
pearCalc is a calculator, application-launcher and text replacement tool. pearCalc's main window contains just a text field, therefore it uses almost no space on the screen.
PEMDAS is a scientific calculator with an easy-to-use interface for doing calculations with formulas and variables.
PlainCalc is a buttonless, algebraic-entry, mathematical calculator with variables.
Wcalc is a very capable calculator. It supports abitrary precision, has
standard functions (sin, asin, and sinh for example, in either radians or
degrees), many pre-defined constants (pi, e, c, etc.), support for using
variables, "active" variables, a command history, hex/octal/binary input and
output, unit conversions, embedded comments, and an expandable expression entry
field. It evaluates expressions using the standard order of operations.